The present invention relates to an improved silent timing chain for automotive or industrial drive applications.
Conventional silent timing chains have been used for many years to transmit power and motion between shafts in automotive applications. The majority of these chains were formed of rows or ranks of toothed links interleaved with adjacent rows of toothed links and having aligned apertures receiving pivot means to join the rows and provide articulation of the chain as it passes around the driving and driven sprockets. Guide links were utilized on the outside edges of alternate rows of links in the chain to position the chain laterally on the sprockets. Each row of links engaged the sprocket teeth on either their inner flank or their outer flank, and each joint was supported by the links in one row. Each tooth on the driving sprocket transferred load to the chain, which offered a smooth engagement with the sprocket and quiet operation.
Silent chains were also produced using block constructions in the early 1900's. However, their usefulness was limited due to their low strength and they were replaced by the silent chains previously described. The engagement characteristics of these early block chains are unknown, but it is likely that such chains were constructed by omitting the inside links in the guide row without compensating for the lack of interleaved links present in conventional silent chains, such that contact was sporadic with every other tooth. Other types of timing drive chains involve the use of roller chains, especially in industrial applications.
Also, double angle, straight-sided sprocket tooth flanks have been used in the past, however, it is believed that the only purpose for the chamfer at the tip of the tooth was for link clearance during engagement and disengagement processes.